Drying apparatus.



T W. E. PRINDLE.

DRYING APPARATUg.

APPLICATION FILED NOV. 11, 1912. I

Patented Feb. 3,1914. 2 SHEETS-SHEET 1 1 .0," v o w :U H W u mwwvww Ml 14 in: 1 z w x w m w Id l. Y K K n W. E. PRLND-LE. DRYING APPARATUSJAPPLICATION FILED NOV. 11, 1912.

Patented Feb. 3, 191

2 sums-sum 2.

UNITED STATES PATENT orrron;

WILLIAM rnrnnrin, or MAnIroWoc, Wiscons n.

, DRYING APPARATUS.

Specification of Letters Patent." Patented Feb. 3, 19 1 1.

Original application filed lfebmary 28, 1912, Serial No. 63 4. Dividedand this application filed November To all whbroit may concern Be itknown that I, WILLIAM E. Pninnm, a citizen of the United States, and aresident ofManitowoc, in the county of Manitowoc and State of.Wisconsin, have invented certo animproved type of mechanical drieradapted for use in dryingwet material; and

- is a divisional application of my co-pending application for a drier,Serial No. 680,464, filed February twenty-eighth, 1912.

One of the principal objects of my inven-' tion is the provision of animproved drying apparatus wherein high temperatures are eifectivelyemployed and applied where the material is wet and.cold,fcorrespondingly reduced temperatures where the ma-.

terial is partly dried, and low temperatures where the dry'ingiscompleted; and another objectof my invention the provision of novelmeans in a drier adapted to control the admission of cold air therein 1forthepurpose of quickly cooling downthedrier when desired. Y

These together with such other ob ects as may hereinafter appear orare.v incident to my invention I- attain'by means of a con s'tr'uotionillustrated 'whereimg I Figure-Lisa longitudinal sectional v ew of myimproved,- apparatus; the cylinders therein being shown ,broken away inorder to accommodate the figure in the-drawing.

Figure 2 is a modification of the structure in Figure 1'. V

Figure 3 is an enlarged sectional view of" the rear, end ofthe drier asshown in Figure 1.

Figure dis a rearelevationof Figure 1.} gure 5 is a section'through theappara-.

Fi tus on the line II of Figure A Broadly s eaking, the: inventioncemprises the app ication of graduated temperatures to the material inthejdrier, ranging from the desired high temperature at a point .wherethe wet and cold material en'- ters, to a correspondinglylow temperaturetoward the rear end of the daierwherethe material is in a drystate, suchapplication" resulting the material vbeing discharged as a umformlydried product and without the occasionrequires.

dried material to any suitable depository. iC en-t-rally suspendedwithin the drier 6 is I Serial No. 730,569.

is'ian improvement on the method adopted in the type of drier commonlyin use.- In a more exclusive sense the present invention purposes toprovidenovel means in an apparatus of the character described wherebythe interior-of the drier can be quickly and positively cooled down toany desired extent .as

In carrying out my invention, as illus- 'trated in the preferred form inthe ac co1npanying drawings, I provide a drier shell or outer cylinderfipreferably lying at an angle to the horizontal, and adapted to haverotation through a gear 7 thereon having driving engagement with .apinion '8 mount-- cd for movement on thelbase 9 and driven from anysuitable source ofpower at hand. The rear or discharge end of thecylinder has free rotative movement within a flanged hood l0 securelymounted on a base 11 and further held in position by the braces 12, thesaid hood being. conformed to entirely in, close the rear end of thecylinder any.longi 'Si) tudinal creeping thereof being provided againstthrough thrust rollers 13-, which bear against vertical shoulders oftires peripherally formed on the drier.

The hood 10 at the rear end of the drier;g5 is further provided with adischarge hop" per 14 leading from the discharge'end of the cylinder-toa receptacle 15 within which I provide a conveyor l6-for conveying the Man niner hot air conveyor 17 extending longitudinally therethrough, andhaving its" rear end 17 projecting through the hood 10 and its forwardend 17 in communication 5 with a'tempei'ing or furnace chamber 18,

or other source of heat, preferably through a fixed extension; 19 aboutwhich it is adapted to rotate. Y

- Surrounding'theforward end -17 of the oo inner cylinder and providinga bearing 4 therefor, is a stationary bonnet 20 mounted on a base 21 andhaving connection with an exhaust. fan 22 by means of a funnel 23.

The bonnet, which carries a feeding member 2'4, opens into the feed endof the drier,

and an annular shoulder-interiorly formed on the drierfrustum connection25'ro'tates about a bearing surface on the bonnet.

The hot air'conveyeris suspended within which have their outerextremities bolted to the inner walls of the outer chamber. The

inner portion ofthe spider 26 is fastened to the outer walls of theinner cylinder so that both cylinders have similar rotative movement,and the inner portion of the spider 27 carries a ring 27 having peripheral contact only with the inner cylinder in order to allow for anyexpansion or con- .traction of the cylinders.

Arranged at intervals along the length of the inner chamber are a seriesof outlet openings 28 which are preferably protected from the materialin the drier by elongated hoods 29 which have their openings directedtoward the rear end of the drier. This arra'ngement permits the heatedair which enters the conveyer from "the tempering chamber to passthrough ,the hooded openings,

7 and also affords opportunity for the highest temperatures passingthrough the outlets adjacent the feed end to come directly in contactwith the material which at this point is .wet and cold. The heated gasescirculating in the drier and also passing through the conveyer graduallypart with their heat through absorption and radiation, so thatmoderating temperatures are applied to the partly dried material on itsprogression rearwardly, graduating to comparatively low temperatures atthe rear end where the drying operation is completed. The suction fancreates and maintains a constant circulation of heated air passingthrough the entire series of outlets to the material as it is cascaded,the heated air moving at constantly decreasing velocity and atdiminishing temperatures as the material in its progression toward thehopper becomes drier and lighter until the material is finallydischarged amid gasesof a very low temperature moving at a very lowvelocity.

The wet material is first fed into the front end of the drying chamberthrough the spout 24c and during the revolving of the apparatus iscascaded by the longitudinal lifting blades 30 bolted on the inside ofthe drying chamber and the lifting blades 31 similarly secured to theouter walls of the inner cylinder.

Referring now more particularly to Figure 3 it will be seen that theinner cylinder has its walls perforated for a slight portion of itslength to provide a series of annular ports 32, the ports being locatedwithin the drier andin close proximity to the hood, and

' surrounded and protected against the entrance of foreign matter by ashield 33 having its opening 34: facing rearwardly. These ports normallyserve the same purpose as the outlets 28, but they also have anadditional function as will be explained.

, In this connection I provide a reciprocating piston 35, within theconveyer and ad-' jacent the rear end thereof, to normally close theopening inthe projecting end which opens to the atmosphere. This pistoncarries a rod 36 operating in guide members 37, 37, which rod is adaptedto impart longitudinal movement to the piston inwardly to a positioneither in part or wholly past the'ports 3'2, permitting the induction ofcold air into the drier by the suction fan to any desired extent throughthe said opening- 1'7 and the ports 32. It is apparent then that thepiston has movement to and from operative position to open and close theports, and is provided to regulate temperatures and control the'admission of cool air in the drier.

The modified construction as disclosed in Figure 2 shows the tires 7peripherally mounted on the projecting ends 17 and 17 of the conveyer 17instead of on the outer shell as in Figure 1. arrangement is simple andeconomical, and is particularly advantageous when applied to the smallermakes of drying machines.

Having thus described my-invention and illustrated-its use, What I claimto be new and desire to secure by Letters Patent is the following I 1.In a drier, the combination with aninclosed drying chamber provided witha feed member and a discharge outlet, of an inner cylinder having oneend thereof leading to a source of heat and its other end extendingthrough the drying chamber, and means to provide communication betweenthe inclosed drying chamber and the atmosphere through the innercylinder.

2. In a mechanical drier, of a closed outer shell, an inner conveyerhaving communication at one end with a source of heat and having itsother end opening outwardly through the shell to the atmosphere, saidinner conveyer being provided with outlet openings in itswalls, andmeans to control the admission of cool air into the drier through thesaid conveyer.

It is obvious that this improved the combination 3. In a dryingapparatus, the combination air cylinder having one end thereof opening.

to the atmosphere and provided witha port in its walls affording apassage for the hot air therefrom to the drying shell, and a piston inthe cylinder normally closing the opening in the rear end thereof andmounted for Operative movement substantially to a position past the saidport.

, closes the rear end thereof and when moved to operative positionadmits cool air into the drier through said ports.

6. In a drier, an outer shell, an inner hot air cylinder projectingthrough the outer shell andhaving that portion of its length within theshell perforated for the passage of hot air to the outer shell, a pistoninthe cylinder, and means to actuate the piston.

7. In an apparatus of thecharacter de Y scribed, an outer cylinderhaving a feed -member and discharge means, an inner cylinder suspendedtherein having communication with a source of heat and having one endthereof opening to the atmosphere, the walls of the said inner cylinderbeing perforated to provide a communicating passage for the heated airto the outer cylinder, an annular shield surrounding the said passagehavingits opening facing in a direction toward the discharge end of thedrier,- and reciprocating means in the inner cylinder which on actuationopens and closes the said passage to the atmosphere.

8. In a drier, the combination of an inclosed drying chamber providedwith a feed member and a discharge outlet, an inner cylindercommunicating with a source of heat and lying in the drying chamber, and

means to provide communication between the; drying chamber and theyatmosphere through the inner cylinder. v

9. In an apparatus of the character described, an outershell, an innercylindrical conveyer extending through the walls of the shell, one'endthereof communicatingwith a source of heat and the other end opening tothe atmosphere, said conveyer being provided with a series of guardedairpassages in its walls leading to the outer shell, and

reciprocating means to open and close the open end of the conveyer,whereby cool air is admitted into the outer shell through the said airpassages, substantially as described.

10. In a rotaryidrier, the combination of an outer inclosed shellhavinga feed opening at its forward end and a discharge outlet at itsrear end, an inner hot air conveyer extending through the shell andprovided with an opening at its forward end leading to a source of heat,said conveyer having its walls perforated at intervals along itsinclosed length and soarranged that highest-temperatures are directedtomaterial when first fed into the interior of the drier with theapplication of correspondingly diminishing temperatures to the materialas it parts with its moisture, and a controlling member normally closingthe rear and of the conveyer and adapted tohave movement therein topermit the entrance of cool air into the drier, in the manner setforth.-

11. In adrier, the combination of an inclosed drying chamberprovidedwith a feed member and a discharge outlet, an inner cylindercommunicating with a source of heat and lying in the' drying chamber,and means to provide communication between the drying chamber and theatmosphere through the inner cylinder, including a valvular device forcontrolling the admissionof air. p 1

In testimony whereof I have hereunto signed my name in the presence ofthe two subscribed witnesses.--.

I WILLIAM E. PRINDLE. I Witnesses: i

J. NASH, v 'GRETHE HALVORSEN.

